Apparatus and method for increasing oxygen levels in a liquid

ABSTRACT

Apparatus and method for increasing dissolved oxygen levels in a liquid. An oxygenation system ( 100 ) includes a liquid source ( 102 ) from which liquid is introduced into a piping network ( 106 ) by a pump ( 104 ). Colloidal minerals are injected into the liquid in a dwell chamber ( 110 ). The mixture of liquid and minerals flows into an oxygenator ( 118 ) where gaseous oxygen is injected into the liquid. The resulting two-phase flow stream is accelerated to supersonic speeds through a linear flow accelerator ( 126 ) comprising a flat Venturi ( 130 ) and electromagnets ( 128 ) positioned adjacent the flat Venturi. The electromagnets generate an electromagnetic field to exert a force on the two-phase mixture in the direction of the flow. The flow stream then passes through a laminar flow grid ( 132 ) to remove turbulence, after which the oxygenated liquid is bottled at a bottling system ( 134 ).

FIELD OF THE INVENTION

[0001] The invention generally relates to fluid processing systems andmore particularly to an apparatus and method for increasing the level ofdissolved oxygen in a fluid.

BACKGROUND OF THE INVENTION

[0002] Oxygen enriched beverages have become more popular in recentyears.

[0003] Oxygenated sports drinks (including water) have sought to enhanceathletic performance by increasing oxygen levels in the bloodstream ofthe consumer. Researchers are continuing to discover other non-athletic,physiological benefits of oxygenated beverages.

[0004] At standard temperature and pressure, oxygen exists in a gaseousstate.

[0005] Oxygen (O₂) normally makes up about 21% of the air in theatmosphere. If oxygen is mixed with a liquid in an open container, theoxygen will migrate to the atmosphere when the mixture is atequilibrium. To preserve the oxygen content of the mixture, the mixturemust be sealed before the oxygen migrates to the atmosphere.

[0006] There are various ways to transfer mass from a gas into a liquid.A first way is to provide a large liquid-gas boundary area through whichgas may be absorbed into the liquid. A second way is to provide adriving force between the gas and liquid phases. The magnitude of thedriving force directly correlates with the mass transfer rate. A thirdway is to increase the mass transfer coefficient by increasing therelative velocity between the interfacing gas and liquid phases, and toincrease the turbulent mixing in the liquid phase. There have beenvarious patents issued for systems and methods for oxygenating liquids.For example, U.S. Pat. No. 6,120,008 issued to Littman et al. (Littman'008) teaches a process for enriching a liquid with oxygen. The Littman'008 process includes flowing the liquid through a pipe and injectinggaseous oxygen into the liquid. The mixture is then flowed through anozzle to accelerate the flow to supersonic speeds. In returning tosubsonic speeds, a shock wave is formed in the flow. The shock wavebreaks up the bubbles of oxygen formed in the liquid. In creating themicroscopic bubbles, the liquid-gas boundary surface area greatlyincreases and enhances the process of transferring mass from the gasinto the liquid.

[0007] U.S. Pat. No. 6,250,609 issued to Cheng et al. (Cheng '609)teaches a process for producing oxygenated liquid. Cheng '609 alsoteaches to mix ozone (O₃) with the liquid prior to mixing the oxygen(O₂) with the liquid. The ozone acts to destroy bacteria and remove theodor and harmful organic compounds that may be in the liquid.

[0008] U.S. Pat. No. 5,925,292 issued to Zeisenis (Zeisenis '292)teaches a process where oxygen is injected into a liquid. The liquid ismoved downwardly through a vertically extending outer vortex and thenback upwardly through a vertically extending inner vortex, and oxygen isintroduced upstream or at the point of reversal. Zeisenis '292 furtherteaches the oxygenated liquid to a magnetic field to induce asubstantial Zeta potential. The Zeta potential, or electrokineticpotential, is a measure of a dispersion stability of charged particlesin solution.

[0009] Although prior art systems may be found operable in producingoxygenated liquids, there remains a need for improvements to increasethe oxygen concentration in oxygenated liquid and to increase theretention rates of oxygen within the liquid over time.

SUMMARY OF THE INVENTION

[0010] The present invention is directed to an apparatus and method forincreasing dissolved oxygen levels in a liquid.

[0011] In accordance with preferred embodiments, an oxygenation systemincludes a piping network, a pump or other pressure source to circulatethe liquid through the piping network to create a flow stream, and aliquid source to provide the liquid to the piping network. Liquidpassing through the piping network discharges from the pump and passesto an ozonator connected to the piping network for injecting gaseousozone into the liquid. Colloidal minerals are injected into the liquidin a dwell chamber at a desired concentration.

[0012] The mixture of liquid and minerals flows into an oxygen injectorconnected to the piping network which injects gaseous oxygen into theliquid to form a two-phase flow stream. The mixture passes through adispersal grid to more uniformly distribute the bubbles in the flowstream.

[0013] The two-phase flow stream is accelerated to supersonic speeds bya linear flow accelerator comprising a flat Venturi connected to thepiping network and electromagnets positioned adjacent the flat Venturi.The Venturi has a substantially elliptically shaped internalcross-sectional area and opposing, substantially flat exterior surfaces.The electromagnets are disposed adjacent the substantially flat exteriorsurfaces and exert a force on the two-phase mixture in the direction ofthe flow.

[0014] The accelerated flow stream passes through a laminar flow grid tomake the flow laminar as it reaches the bottling system, where theoxygenated liquid is bottled. Excess oxygenated liquid is collected andcirculated back to the ozonator for reprocessing.

[0015] These and various other features and advantages that characterizethe present invention will become apparent upon reading the followingdetailed description and upon review of the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a flow schematic showing an oxygenation system foroxygenating a liquid in accordance with an embodiment of the presentinvention.

[0017]FIG. 2 is a side elevation view of a linear flow accelerator inaccordance with an embodiment of the present invention.

[0018]FIG. 3 is a front elevation view of a linear flow accelerator inaccordance with an embodiment of the present invention.

[0019]FIG. 4 is an end elevation view of a linear flow accelerator inaccordance with an embodiment of the present invention.

[0020]FIG. 5 is a chart showing the oxygen concentration in oxygenatedwater prepared by the method of the present invention.

DETAILED DESCRIPTION

[0021]FIG. 1 is a schematic diagram showing the flow of liquid throughan oxygenation system 100. In one embodiment, the liquid is spring wateror mineral water, but other types of drinks, such as sports drinks, mayalso be used. The flow begins by pumping the liquid from a reservoir102. The liquid is supplied to a pump 104 and exits the pump 104 at adesired pressure. Although the system 100 has a pump 104 for supplyingpressure to the liquid in the piping network 106, it is contemplatedthat the water may be also supplied from an elevated reservoir so thatno additional pressure is required.

[0022] After leaving the pump 104, the liquid flows through an ozonator108 where ozone is generated and injected into the liquid to sterilizethe liquid. The ozone destroys bacteria in the liquid and removes odorand harmful organic compounds from the liquid.

[0023] The liquid flows from the ozonator 108 to a dwell chamber 110. Inthe dwell chamber 110, colloidal minerals are injected into the liquid.The colloidal minerals are stored in a mineral reservoir 112 andinjected into the dwell chamber 110 by positive displacement pumps. Thedwell chamber 110 is sized in relation to the desired flow through thesystem 100 and the desired rate of mineral injection into the flow.

[0024] Colloidal minerals are characterized by having electrostaticadsorption of ions to the surface of a colloidal particle. Thisadsorption creates a primary adsorption layer that in turn creates asubstantial adsorption layer at the surface of the colloidal particle.This surface charge performs two functions: (1) the surface chargecauses a repulsion to exist between two particles when they approacheach other, and (2) the surface charge attracts oppositely charge ionsinto the vicinity of the particles. As a result, an ion “cloud” or“double layer” forms in a solution around the charged particles and theions are dispersed throughout the liquid.

[0025] The thickness of this ion cloud determines how close twoparticles can approach each other before the two particles startexerting repulsive forces on one another. The size of this ion clouddepends on the magnitude of the surface charge which depends on thesolution concentration of the adsorption ion and the concentration ofthe electrolyte in solution. Examples of suitable colloidal mineralsinclude aluminum, sulfur, iron and fluoride.

[0026] The liquid that exits the dwell chamber 110 flows through liquidsampling instruments 114. The liquid sampling instruments 114 preferablyconsist of conventional instrumentation to measure the fluid flow rate,the fluid pressure, and fluid temperature and the instrumentscommunicate this fluid flow information to a control processor 116. Thecontrol processor 116 is part of a computer (PC) based control systemthat regulates the various inputs to the oxygenation system 100 inresponse to information acquired by the liquid sampling instruments 114.

[0027] Downstream of the liquid sampling instruments 114, oxygen (O₂) isinjected into the flow stream by an oxygen injector 118. The oxygensupplied to the oxygen injector 118 comes from an oxygen tank 120through an oxygen injection tube 122. Instruments (not shown) on theoxygen injection tube 122 monitor and regulate the amount of oxygeninjected into the flow stream and communicate this information to thecontrol processor 116.

[0028] After oxygen is injected into the flow stream, the flow streamconstitutes a two-phase flow stream made up of a mixture of liquid,colloidal minerals and gaseous oxygen in the form of gas bubbles.Downstream of the oxygen injector 118, the two-phase mixture passesthrough a dispersal grid 124. The dispersal grid 124 is preferably astainless steel wire mesh. The dispersal grid 124 causes the oxygenbubbles to become evenly distributed throughout the flow stream andcauses the oxygen bubbles to become more uniform in size.

[0029] The two-phase mixture then flows through a linear flowaccelerator 126. The linear flow accelerator 126 comprises a flatVenturi 128 with electromagnets 130 positioned adjacent the flat Venturi128. The linear flow accelerator 126 is more fully described below inthe description of FIGS. 2-3. The linear flow accelerator 126accelerates the flow to supersonic speeds. The speed of sound in thetwo-phase mixture of liquid and oxygen bubbles is on the order of 15meters per second (50 feet per second), although it varies depending onthe concentrations of the liquid and oxygen in the mixture. Bycomparison, the speed of sound in air is about 330 meters per second(1,100 feet per second) and the speed of sound in water is about 1,500meters per second (5,000 feet per second).

[0030] The two-phase flow is decelerated at the exit of the linear flowaccelerator 126 to return the flow to subsonic speeds. The supersonicflow decelerates to subsonic flow across a thin region known as a shockwave. The shock wave breaks up the oxygen bubbles into microscopicbubbles to promote mixing of the liquid and gas bubbles.

[0031] The subsonic mixture exits the linear flow accelerator 126 andenters the laminar flow grid 132. In one embodiment, the laminar flowgrid 132 is a collection of parallel, tightly-packed and thin tubes witheach tube having a diameter much less than the length of the tube. Anindividual tube resembles an ordinary drinking straw. In anotherembodiment, the laminar flow grid 132 is a block of cylindricalmaterial, such as polyvinylchloride (PVC), with numerous parallel holesdefined within the block. The laminar flow grid 132 receives theturbulent flow from the linear flow accelerator 126 and dischargeslaminar flow.

[0032] The flow that exits the laminar flow grid 130 then flows to abottling system 134 where the oxygenated liquid is placed into bottles(one shown at 135). Excess flow of the liquid is returned to theozonator by pipe 136. The returned liquid is passed through returnliquid instrumentation 138 to measure a flow rate and a temperature ofthe returned liquid. This information is provided to the controlprocessor 116 to regulate the flow of minerals to the system 100.

[0033]FIGS. 2 and 3 show a side elevation view and a front elevationview of the linear flow accelerator 126. The linear flow accelerator 126includes the aforementioned flat Venturi 130 (a converging/divergingnozzle) electromagnets 128. The electromagnets 128 are positionedadjacent opposed flat sides of the flat Venturi 130. The Venturi 130 isformed from a length of cylindrical deformable tubing with opposing flatsides formed over a portion of the length of the Venturi 130, as shownin an end elevation view in FIG. 4. The flow through the Venturi 130accelerates from a subsonic speed in an entrance region of the Venturi130 to the speed of sound at a throat of the Venturi 130. The flowcontinues to accelerate to supersonic speed through the Venturi 130 andthen decelerates rapidly across a shock wave formed as the flow exitsthe Venturi 130. As noted above, the speed of sound for the two-phasemixture of liquid and oxygen is on the order of 15 meters per second (50ft/sec).

[0034] The Venturi 130 does not have a conventional axisymmetricconfiguration, but rather is characterized as flat Venturi, as shown inFIG. 4. More particularly, the Venturi has a substantially ellipticallyshaped internal cross-sectional area that is smaller than thecross-sectional areas of the passageway immediately upstream anddownstream from the Venturi. This particular geometry facilitatesplacement of the electromagnets adjacent opposing, substantially flatexterior surfaces 139 of the Venturi 130, providing closer, more uniformapplication of an electromagnetic field across the flow stream withinthe Venturi. The electromagnetic field exerts forces on the colloidalminerals in the liquid. The electromagnets 130 are preferably polarizedsuch that the electromagnetic field aligns with the direction of flow(downward in FIG. 2). The strength of the electromagnetic field isdetermined by the electrical current that flows through coils 140wrapped around a core 142 of the electromagnet. It has been observedthat the electromagnets 130 cause the flow deceleration across astronger shock wave than would otherwise be present for the flat Venturi128 alone. The stronger shock wave in turn causes the resultantmicroscopic bubbles downstream of the shock wave to be smaller andcauses better mixing of the fluid and oxygen. The reduction in size ofthe bubbles also causes the liquid-gas boundary to be larger andpromotes greater mass transfer of the oxygen into the liquid. It is alsobelieved that the flow in the linear flow accelerator 126 advantageouslyincreases the Zeta potential of the mixture of liquid and oxygen gas.

EXAMPLE

[0035] A prototype system 100 conforming to that shown in FIG. 1 wasbuilt for the oxygenation of spring water. The spring water was filteredto 5 microns (5×10⁻⁶ meter) and presented with the following nominalcharacteristics: Total dissolved solids = 26-30 parts per million; pH =6.1; Initial dissolved oxygen levels = 7.2 milligrams per liter; andTemperature = 14° C.(57° F.).

[0036] The liquid pump 104 supplied the spring water to the system at193 kilopascal (28 psi) at a flow rate of 114 liters per minute (30gallons per minute). The piping for the piping network 106 between thepump 104 and the linear flow accelerator 126 had a nominal diameter of3.8 cm (1.5 inches). The ozonator 108 had a volume of 246 liters (65gallons) and a flow capacity of 132 liters per minute (35 gallons perminute).

[0037] The colloidal minerals used were produced by The RocklandCorporation, Tulsa, Okla., United States of America, under the trademarkBody Booster. These minerals are derived from humic shale and consist ofapproximately 72 identified compounds including sulfur, aluminum,fluoride, iron, calcium and carbon.

[0038] The oxygen was supplied to the water by the oxygenator 118 at apressure of 227 kilopascals (33 psi) or about 34 kilopascals (5 psi)greater than the water pressure. The holes in the dispersal grid 124were approximately 1.6 millimeters ({fraction (1/16)}th of an inch) indiameter.

[0039] The flat Venturi 130 was created by heating a length of acrylictubing and then deforming the length of tubing to form opposed flatportions as shown in FIGS. 2 and 4. The undeformed tubing had a nominalinner diameter of about 5.8 cm (2 inches). The deformed length of tubingwith a substantially elliptical cross section was about 30.48 cm (12inches) in length. The flattened surfaces 139 had dimensions ofapproximately 6.4 cm (2.5 inches) by 0.32 cm (0.125 inches). Theelectromagnet cores 142 had a dimension of 17.8 cm (7 inches) by 5.1 cm(2 inches).

[0040] Tests were performed on the water at times related to thebottling process. An initial test was performed to obtain an “initial”oxygen concentration in the water at the time of bottling. Samples ofthe bottled oxygenated water were taken to a laboratory for testing.Tests were performed to measure the oxygen concentration immediatelyafter opening each bottle. The bottles were left open to the atmosphereand tested after the passage of 24 hours. The results of these tests forsix sample runs under various operating conditions are presented in FIG.5.

[0041] It is readily seen that the oxygen concentration is greatlyincreased by a factor of about 6-7 by the process described above, ascompared to the initial concentration of oxygen in the water. Ingeneral, the initial oxygen concentrations varied from about 38milligrams per liter (mg/l) to about 46 mg/l. These results show theefficiency of the system 100.

[0042] It is clear that the present invention is well adapted to attainthe ends and advantages mentioned as well as those inherent therein.While presently preferred embodiments of the invention have beendescribed for purposes of the disclosure, it will be understood thatnumerous changes can be made which will readily suggest themselves tothose skilled in the art. Such changes are encompassed within the spiritof the invention disclosed and as defined in the appended claims.

1. A system for increasing dissolved oxygen levels in a liquid,comprising: a piping network defining an interior passageway; a liquidsource which introduces a liquid into the piping network to form a flowstream; a dwell chamber connected to the piping network which injectscolloidal minerals at a desired concentration into the flow stream; anoxygen injector connected to the piping network which injects gaseousoxygen into the flow stream at a desired level; a linear flowaccelerator connected to the piping network to accelerate the flowstream, comprising: a flat Venturi having a substantially ellipticallyshaped internal cross sectional area smaller than respective crosssectional areas of the passageway immediately upstream and downstream ofthe flat Venturi; and an electromagnet adjacent the flat Venturi andaligned along a major axis of the substantially elliptically shapedinternal cross sectional area which applies a magnetic field of desiredfield strength to the flow stream in the flat Venturi, wherein the flowstream is accelerated to supersonic speed through the linear flowaccelerator and subsequently decelerated to subsonic speed as the flowstream exits the linear flow accelerator with the transition fromsupersonic to subsonic speed inducing a shock wave in the flow stream tobreak up oxygen bubbles in the liquid; and a laminar flow grid connectedto the piping network downstream from the linear flow accelerator toremove turbulence from the flow stream.
 2. The system of claim 1 whereina positive displacement pump injects the colloidal minerals into theliquid in the dwell chamber.
 3. The system of claim 1 further comprisinga bottling system connected to the piping network downstream from thelaminar flow grid which places the liquid in bottles.
 4. The system ofclaim 1 further comprising a dispersal grid connected to the pipingnetwork between the oxygen injector and the linear flow accelerator tonominally uniformly distribute oxygen bubbles throughout the flowstream.
 5. The system of claim 1 further comprising an ozonatorconnected to the piping network upstream from the oxygenator to injectozone into the flow stream to sterilize the liquid.
 6. The system ofclaim 1 wherein the flat Venturi further has opposing, substantiallyflat exterior surfaces aligned with the major axis of the substantiallyelliptically shaped internal cross-sectional area, and wherein theelectromagnet is disposed adjacent a selected one of the flat exteriorsurfaces.
 7. The system of claim 6 wherein the flat Venturi is formed byproviding a length of tubing with a substantially circular shapedinternal cross-sectional area, and selectively deforming the length oftubing to produce the substantially elliptically shaped internalcross-sectional area and the substantially flat exterior surfaces.
 8. Amethod for producing oxygenated liquid, comprising: (a) introducing apressurized liquid into a piping network to form a flow stream; (b)adding colloidal minerals at a desired concentration to the flow stream;(c) injecting gaseous oxygen into the flow stream to produce a flowingmixture of liquid and gaseous oxygen bubbles; (d) providing a linearflow accelerator including a flat Venturi having a substantiallyelliptically shaped internal cross sectional area and an electromagnetadjacent the flat Venturi and aligned along a major axis of thesubstantially elliptically shaped internal cross sectional area whichapplies a magnetic field of desired field strength across the flatVenturi; and (e) passing the flowing mixture of liquid and gaseousoxygen bubbles through the linear flow accelerator to accelerate theflowing mixture to supersonic speed and to subsequently decelerate theflowing mixture to subsonic speed to break up the gaseous oxygenbubbles.
 9. The method of claim 8, further comprising a step ofproviding a dispersal grid upstream from the linear flow accelerator tonominally uniformly distribute oxygen bubbles throughout the flowstream.
 10. The method of claim 8, further comprising a step ofproviding a laminar flow grid downstream from the linear flowaccelerator to remove turbulence from the flowing mixture exiting thelinear flow accelerator.